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Tamisier L, Fabre F, Szadkowski M, Chateau L, Nemouchi G, Girardot G, Millot P, Palloix A, Moury B. Within-plant genetic drift to control virus adaptation to host-resistance genes. PLoS Pathog 2024; 20:e1012424. [PMID: 39102439 DOI: 10.1371/journal.ppat.1012424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 07/01/2024] [Indexed: 08/07/2024] Open
Abstract
Manipulating evolutionary forces imposed by hosts on pathogens like genetic drift and selection could avoid the emergence of virulent pathogens. For instance, increasing genetic drift could decrease the risk of pathogen adaptation through the random fixation of deleterious mutations or the elimination of favorable ones in the pathogen population. However, no experimental proof of this approach is available for a plant-pathogen system. We studied the impact of pepper (Capsicum annuum) lines carrying the same major resistance gene but contrasted genetic backgrounds on the evolution of Potato virus Y (PVY). The pepper lines were chosen for the contrasted levels of genetic drift (inversely related to Ne, the effective population size) they exert on PVY populations, as well as for their contrasted resistance efficiency (inversely related to the initial replicative fitness, Wi, of PVY in these lines). Experimental evolution was performed by serially passaging 64 PVY populations every month on six contrasted pepper lines during seven months. These lines exhibited highly divergent evolutionary trajectories, ranging from viral extinctions to replicative fitness gains. The sequencing of the PVY VPg cistron, where adaptive mutations are likely to occur, allowed linking these replicative fitness gains to parallel adaptive nonsynonymous mutations. Evolutionary trajectories were well explained by the genetic drift imposed by the host. More specifically, Ne, Wi and their synergistic interaction played a major role in the fate of PVY populations. When Ne was low (i.e. strong genetic drift), the final PVY replicative fitness remained close to the initial replicative fitness, whereas when Ne was high (i.e. low genetic drift), the final PVY replicative fitness was high independently of the replicative fitness of the initially inoculated virus. We show that combining a high resistance efficiency (low Wi) and a strong genetic drift (low Ne) is the best solution to increase resistance durability, that is, to avoid virus adaptation on the long term.
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Affiliation(s)
- Lucie Tamisier
- Pathologie Végétale, INRAE, Montfavet, France
- GAFL, INRAE, Montfavet, France
| | | | - Marion Szadkowski
- Pathologie Végétale, INRAE, Montfavet, France
- GAFL, INRAE, Montfavet, France
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2
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Mbewe W, Mukasa S, Ochwo-Ssemakula M, Sseruwagi P, Tairo F, Ndunguru J, Duffy S. Cassava brown streak virus evolves with a nucleotide-substitution rate that is typical for the family Potyviridae. Virus Res 2024; 346:199397. [PMID: 38750679 PMCID: PMC11145536 DOI: 10.1016/j.virusres.2024.199397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 05/08/2024] [Accepted: 05/12/2024] [Indexed: 05/25/2024]
Abstract
The ipomoviruses (family Potyviridae) that cause cassava brown streak disease (cassava brown streak virus [CBSV] and Uganda cassava brown streak virus [UCBSV]) are damaging plant pathogens that affect the sustainability of cassava production in East and Central Africa. However, little is known about the rate at which the viruses evolve and when they emerged in Africa - which inform how easily these viruses can host shift and resist RNAi approaches for control. We present here the rates of evolution determined from the coat protein gene (CP) of CBSV (Temporal signal in a UCBSV dataset was not sufficient for comparable analysis). Our BEAST analysis estimated the CBSV CP evolves at a mean rate of 1.43 × 10-3 nucleotide substitutions per site per year, with the most recent common ancestor of sampled CBSV isolates existing in 1944 (95% HPD, between years 1922 - 1963). We compared the published measured and estimated rates of evolution of CPs from ten families of plant viruses and showed that CBSV is an average-evolving potyvirid, but that members of Potyviridae evolve more quickly than members of Virgaviridae and the single representatives of Betaflexiviridae, Bunyaviridae, Caulimoviridae and Closteroviridae.
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Affiliation(s)
- Willard Mbewe
- Department of Biological Sciences, Malawi University of Science and Technology, P. O. Box 5196, Limbe, Malawi.
| | - Settumba Mukasa
- School of Agriculture and Environmental Science, Department of Agricultural Production, P. O. Box 7062, Makerere University, Kampala, Uganda
| | - Mildred Ochwo-Ssemakula
- School of Agriculture and Environmental Science, Department of Agricultural Production, P. O. Box 7062, Makerere University, Kampala, Uganda
| | - Peter Sseruwagi
- Mikocheni Agricultural Research Institute, P.O. Box 6226, Dar es Slaam, Tanzania
| | - Fred Tairo
- Mikocheni Agricultural Research Institute, P.O. Box 6226, Dar es Slaam, Tanzania
| | - Joseph Ndunguru
- Mikocheni Agricultural Research Institute, P.O. Box 6226, Dar es Slaam, Tanzania
| | - Siobain Duffy
- Department of Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, NJ 08901, United States.
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3
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Lebeda A, Burdon JJ. Studying Wild Plant Pathosystems to Understand Crop Plant Pathosystems: Status, Gaps, Challenges, and Perspectives. PHYTOPATHOLOGY 2023; 113:365-380. [PMID: 36256745 DOI: 10.1094/phyto-01-22-0018-per] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Phytopathology is a highly complex scientific discipline. Initially, its focus was on the study of plant-pathogen interactions in agricultural and forestry production systems. Host-pathogen interactions in natural plant communities were generally overlooked until the 1970s when plant pathologists and evolutionary biologists started to take an interest in these interactions, and their dynamics in natural plant populations, communities, and ecosystems. This article introduces the general principles of plant pathosystems, provides a basic critical overview of current knowledge of host-pathogen interactions in natural plant pathosystems, and shows how this knowledge is important for future developments in plant pathology especially as it applies in cropping systems, ecology, and evolutionary biology. Plant pathosystems can be further divided according to the structure and origin of control, as autonomous (wild plant pathosystems, WPPs) or deterministic (crop plant pathosystems, CPPs). WPPs are characterized by the disease triangle and closed-loop (feedback) controls, and CPPs are characterized by the disease tetrahedron and open-loop (non-feedback) controls. Basic general, ecological, genetic, and population structural and functional differences between WPPs and CPPs are described. It is evident that we lack a focus on long-term observations and research of diseases and their dynamics in natural plant populations, metapopulations, communities, ecosystems, and biomes, as well as their direct or indirect relationships to CPPs. Differences and connections between WPPs and CPPs, and why, and how, these are important for agriculture varies. WPP and CPP may be linked by strong biological interactions, especially where the pathogen is in common. This is demonstrated through a case study of lettuce (Lactuca spp., L. serriola and L. sativa) and lettuce downy mildew (Bremia lactucae). In other cases where there is no such direct biological linkage, the study of WPPs can provide a deeper understanding of how ecology and genetics interacts to drive disease through time. These studies provide insights into ways in which farming practices may be changed to limit disease development. Research on interactions between pathosystems, the "cross-talk" of WPPs and CPPs, is still very limited and, as shown in interactions between wild and cultivated Lactuca spp.-B. lactucae associations, can be highly complex. The implications and applications of this knowledge in plant breeding, crop management, and disease control measures are considered. This review concludes with a discussion of theoretical, general and specific aspects, challenges and limits of future WPP research, and application of their results in agriculture.
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Affiliation(s)
- Aleš Lebeda
- Department of Botany, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
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Moreno‐Pérez MG, Bera S, McLeish M, Fraile A, García‐Arenal F. Reversion of a resistance-breaking mutation shows reversion costs and high virus diversity at necrotic local lesions. MOLECULAR PLANT PATHOLOGY 2023; 24:142-153. [PMID: 36435959 PMCID: PMC9831284 DOI: 10.1111/mpp.13281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 09/28/2022] [Accepted: 10/29/2022] [Indexed: 06/16/2023]
Abstract
An instance of host range evolution relevant to plant virus disease control is resistance breaking. Resistance breaking can be hindered by across-host fitness trade-offs generated by negative effects of resistance-breaking mutations on the virus fitness in susceptible hosts. Different mutations in pepper mild mottle virus (PMMoV) coat protein result in the breaking in pepper plants of the resistance determined by the L3 resistance allele. Of these, mutation M138N is widespread in PMMoV populations, despite associated fitness penalties in within-host multiplication and survival. The stability of mutation M138N was analysed by serial passaging in L3 resistant plants. Appearance on passaging of necrotic local lesions (NLL), indicating an effective L3 resistance, showed reversion to nonresistance-breaking phenotypes was common. Most revertant genotypes had the mutation N138K, which affects the properties of the virus particle, introducing a penalty of reversion. Hence, the costs of reversion may determine the evolution of resistance-breaking in addition to resistance-breaking costs. The genetic diversity of the virus population in NLL was much higher than in systemically infected tissues, and included mutations reported to break L3 resistance other than M138N. Infectivity assays on pepper genotypes with different L alleles showed high phenotypic diversity in respect to L alleles in NLL, including phenotypes not reported in nature. Thus, high diversity at NLL may potentiate the appearance of genotypes that enable the colonization of new host genotypes or species. Collectively, the results of this study contribute to better understanding the evolutionary dynamics of resistance breaking and host-range expansions.
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Affiliation(s)
- Manuel G. Moreno‐Pérez
- Centro de Biotecnología y Genómica de Plantas UPM‐INIA/CSICUniversidad Politécnica de MadridMadridSpain
- E.T.S.I. Agronómica, Alimentaria y de BiosistemasCampus de Montegancedo, UPMMadridSpain
| | - Sayanta Bera
- Centro de Biotecnología y Genómica de Plantas UPM‐INIA/CSICUniversidad Politécnica de MadridMadridSpain
- E.T.S.I. Agronómica, Alimentaria y de BiosistemasCampus de Montegancedo, UPMMadridSpain
| | - Michael McLeish
- Centro de Biotecnología y Genómica de Plantas UPM‐INIA/CSICUniversidad Politécnica de MadridMadridSpain
- E.T.S.I. Agronómica, Alimentaria y de BiosistemasCampus de Montegancedo, UPMMadridSpain
| | - Aurora Fraile
- Centro de Biotecnología y Genómica de Plantas UPM‐INIA/CSICUniversidad Politécnica de MadridMadridSpain
- E.T.S.I. Agronómica, Alimentaria y de BiosistemasCampus de Montegancedo, UPMMadridSpain
| | - Fernando García‐Arenal
- Centro de Biotecnología y Genómica de Plantas UPM‐INIA/CSICUniversidad Politécnica de MadridMadridSpain
- E.T.S.I. Agronómica, Alimentaria y de BiosistemasCampus de Montegancedo, UPMMadridSpain
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5
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Jeger MJ. Tolerance of plant virus disease: Its genetic, physiological, and epidemiological significance. Food Energy Secur 2022. [DOI: 10.1002/fes3.440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Michael John Jeger
- Department of Life Sciences, Silwood Park Imperial College London Ascot UK
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Jin J, McCorkle KL, Cornish V, Carbone I, Lewis RS, Shew HD. Adaptation of Phytophthora nicotianae to Multiple Sources of Partial Resistance in Tobacco. PLANT DISEASE 2022; 106:906-917. [PMID: 34735283 DOI: 10.1094/pdis-06-21-1241-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Host resistance is an important tool in the management of black shank disease of tobacco. Race development leads to rapid loss of single-gene resistance, but the adaptation by Phytophthora nicotianae to sources of partial resistance from Beinhart 1000, Florida 301, and the Wz gene region introgressed from Nicotiana rustica is poorly characterized. In greenhouse environments, host genotypes with quantitative trait loci (QTLs) conferring resistance from multiple sources were initially inoculated with an aggressive isolate of race 0 or race 1 of P. nicotianae. The most aggressive isolate was selected after each of six host generations to inoculate the next generation of plants. The race 0 isolate demonstrated a continuous gradual increase in disease severity and percentage root rot on all sources of resistance except the genotype K 326 Wz/-, where a large increase in both was observed between generations 2 and 3. Adaptation by the race 0 isolate on Beinhart 1000 represents the first report of adaptation to this genotype by P. nicotianae. The race 1 isolate did not exhibit significant increases in aggressiveness over generations but exhibited a large increase in aggressiveness on K 326 Wz/- between generations 3 and 4. Molecular characterization of isolates recovered during selection was completed via double digest restriction-site associated DNA sequencing, but no polymorphisms were associated with the observed changes in aggressiveness. The rapid adaptation to Wz resistance and the gradual adaptation to other QTLs highlights the need to study the nature of Wz resistance and to conduct field studies on the efficacy of resistance gene rotation for disease management.
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Affiliation(s)
- Jing Jin
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Kestrel L McCorkle
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Vicki Cornish
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Ignazio Carbone
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Ramsey S Lewis
- Department of Crop and Soil Science, North Carolina State University, Raleigh, NC 27695
| | - H David Shew
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
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7
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Tamisier L, Szadkowski M, Girardot G, Djian‐Caporalino C, Palloix A, Hirsch J, Moury B. Concurrent evolution of resistance and tolerance to potato virus Y in Capsicum annuum revealed by genome-wide association. MOLECULAR PLANT PATHOLOGY 2022; 23:254-264. [PMID: 34729890 PMCID: PMC8743019 DOI: 10.1111/mpp.13157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 05/21/2023]
Abstract
We performed a genome-wide association study of pepper (Capsicum annuum) tolerance to potato virus Y (PVY). For 254 pepper accessions, we estimated the tolerance to PVY as the coefficient of regression of the fresh weight (or height) of PVY-infected and mock-inoculated plants against within-plant virus load. Small (strongly negative) coefficients of regression indicate low tolerance because plant biomass or growth decreases sharply as virus load increases. The tolerance level varied largely, with some pepper accessions showing no symptoms or fairly mild mosaics, whereas about half (48%) of the accessions showed necrotic symptoms. We found two adjacent single-nucleotide polymorphisms (SNPs) at one extremity of chromosome 9 that were significantly associated with tolerance to PVY. Similarly, in three biparental pepper progenies, we showed that the induction of necrosis on PVY systemic infection segregated as a monogenic trait determined by a locus on chromosome 9. Our results also demonstrate the existence of a negative correlation between resistance and tolerance among the cultivated pepper accessions at both the phenotypic and genetic levels. By comparing the distributions of the tolerance-associated SNP alleles and previously identified PVY resistance-associated SNP alleles, we showed that cultivated pepper accessions possess favourable alleles for both resistance and tolerance less frequently than expected under random associations, while the minority of wild pepper accessions frequently combined resistance and tolerance alleles. This divergent evolution of PVY resistance and tolerance could be related to pepper domestication or farmer's selection.
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Affiliation(s)
- Lucie Tamisier
- Pathologie VégétaleINRAEMontfavetFrance
- GAFLINRAEMontfavetFrance
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8
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Jin J, Shew HD. Impacts of Continued Exposure to a Susceptible Host Genotype on Aggressiveness of Phytophthora nicotianae Isolates Adapted to Multiple Sources of Partial Resistance. PLANT DISEASE 2022; 106:373-381. [PMID: 34282925 DOI: 10.1094/pdis-09-20-1972-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Pathogen adaptation can threaten the durability of partial resistance. Mixed plantings of susceptible and partially resistant varieties may prolong the effectiveness of partial resistance, but little is known about how continued exposure to a susceptible genotype can change the aggressiveness of pathogen isolates adapted to a source of partial resistance. The objective of this study was to examine the effects of continued exposure to a highly susceptible tobacco genotype on isolates of Phytophthora nicotianae that had been adapted to partial resistance. Isolates of P. nicotianae previously adapted to two sources of partial resistance were continually exposed to either the original host of adaptation or a susceptible host. After six generations of host exposure, isolates obtained from the partially resistant and the susceptible hosts were compared for their aggressiveness on the resistant host and for differences in expression of genes associated with pathogenicity and aggressiveness. Results suggested that exposure to the susceptible tobacco genotype reduced aggressiveness of isolates adapted to partial resistance in K 326 Wz/- but not of isolates adapted to partial resistance in Fla 301. Quantification of pathogenicity-associated gene expression using qRT-PCR suggested the rapid change in aggressiveness of isolates adapted to Wz-sourced partial resistance may have resulted from modification in gene expression in multiple genes.
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Affiliation(s)
- Jing Jin
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - H David Shew
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27695
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9
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Langlands-Perry C, Cuenin M, Bergez C, Krima SB, Gélisse S, Sourdille P, Valade R, Marcel TC. Resistance of the Wheat Cultivar ‘Renan’ to Septoria Leaf Blotch Explained by a Combination of Strain Specific and Strain Non-Specific QTL Mapped on an Ultra-Dense Genetic Map. Genes (Basel) 2021; 13:genes13010100. [PMID: 35052440 PMCID: PMC8774678 DOI: 10.3390/genes13010100] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/22/2021] [Accepted: 12/22/2021] [Indexed: 11/16/2022] Open
Abstract
Quantitative resistance is considered more durable than qualitative resistance as it does not involve major resistance genes that can be easily overcome by pathogen populations, but rather a combination of genes with a lower individual effect. This durability means that quantitative resistance could be an interesting tool for breeding crops that would not systematically require phytosanitary products. Quantitative resistance has yet to reveal all of its intricacies. Here, we delve into the case of the wheat/Septoria tritici blotch (STB) pathosystem. Using a population resulting from a cross between French cultivar Renan, generally resistant to STB, and Chinese Spring, a cultivar susceptible to the disease, we built an ultra-dense genetic map that carries 148,820 single nucleotide polymorphism (SNP) markers. Phenotyping the interaction was done with two different Zymoseptoria tritici strains with contrasted pathogenicities on Renan. A linkage analysis led to the detection of three quantitative trait loci (QTL) related to resistance in Renan. These QTL, on chromosomes 7B, 1D, and 5D, present with an interesting diversity as that on 7B was detected with both fungal strains, while those on 1D and 5D were strain-specific. The resistance on 7B was located in the region of Stb8 and the resistance on 1D colocalized with Stb19. However, the resistance on 5D was new, so further designated Stb20q. Several wall-associated kinases (WAK), nucleotide-binding and leucine-rich repeats (NB-LRR) type, and kinase domain carrying genes were present in the QTL regions, and some of them were expressed during the infection. These results advocate for a role of Stb genes in quantitative resistance and for resistance in the wheat/STB pathosystem being as a whole quantitative and polygenic.
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Affiliation(s)
- Camilla Langlands-Perry
- Université Paris Saclay, INRAE, UR BIOGER, 78850 Thiverval-Grignon, France; (C.L.-P.); (M.C.); (C.B.); (S.B.K.); (S.G.)
- ARVALIS Institut du Végétal, 91720 Boigneville, France;
| | - Murielle Cuenin
- Université Paris Saclay, INRAE, UR BIOGER, 78850 Thiverval-Grignon, France; (C.L.-P.); (M.C.); (C.B.); (S.B.K.); (S.G.)
| | - Christophe Bergez
- Université Paris Saclay, INRAE, UR BIOGER, 78850 Thiverval-Grignon, France; (C.L.-P.); (M.C.); (C.B.); (S.B.K.); (S.G.)
| | - Safa Ben Krima
- Université Paris Saclay, INRAE, UR BIOGER, 78850 Thiverval-Grignon, France; (C.L.-P.); (M.C.); (C.B.); (S.B.K.); (S.G.)
| | - Sandrine Gélisse
- Université Paris Saclay, INRAE, UR BIOGER, 78850 Thiverval-Grignon, France; (C.L.-P.); (M.C.); (C.B.); (S.B.K.); (S.G.)
| | - Pierre Sourdille
- Université Clermont–Auvergne, INRAE, UMR GDEC, 63000 Clermont-Ferrand, France;
| | - Romain Valade
- ARVALIS Institut du Végétal, 91720 Boigneville, France;
| | - Thierry C. Marcel
- Université Paris Saclay, INRAE, UR BIOGER, 78850 Thiverval-Grignon, France; (C.L.-P.); (M.C.); (C.B.); (S.B.K.); (S.G.)
- Correspondence:
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10
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Dumartinet T, Ravel S, Roussel V, Perez-Vicente L, Aguayo J, Abadie C, Carlier J. Complex adaptive architecture underlies adaptation to quantitative host resistance in a fungal plant pathogen. Mol Ecol 2021; 31:1160-1179. [PMID: 34845779 DOI: 10.1111/mec.16297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/12/2021] [Accepted: 11/17/2021] [Indexed: 11/26/2022]
Abstract
Plant pathogens often adapt to plant genetic resistance so characterization of the architecture underlying such an adaptation is required to understand the adaptive potential of pathogen populations. Erosion of banana quantitative resistance to a major leaf disease caused by polygenic adaptation of the causal agent, the fungus Pseudocercospora fijiensis, was recently identified in the northern Caribbean region. Genome scan and quantitative genetics approaches were combined to investigate the adaptive architecture underlying this adaptation. Thirty-two genomic regions showing host selection footprints were identified by pool sequencing of isolates collected from seven plantation pairs of two cultivars with different levels of quantitative resistance. Individual sequencing and phenotyping of isolates from one pair revealed significant and variable levels of correlation between haplotypes in 17 of these regions with a quantitative trait of pathogenicity (the diseased leaf area). The multilocus pattern of haplotypes detected in the 17 regions was found to be highly variable across all the population pairs studied. These results suggest complex adaptive architecture underlying plant pathogen adaptation to quantitative resistance with a polygenic basis, redundancy, and a low level of parallel evolution between pathogen populations. Candidate genes involved in quantitative pathogenicity and host adaptation of P. fijiensis were identified in genomic regions by combining annotation analysis with available biological data.
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Affiliation(s)
- Thomas Dumartinet
- CIRAD, UMR PHIM, Montpellier, France.,PHIM, Univ Montpellier, INRAe, CIRAD, Montpellier SupAgro, Montpellier, France
| | - Sébastien Ravel
- CIRAD, UMR PHIM, Montpellier, France.,PHIM, Univ Montpellier, INRAe, CIRAD, Montpellier SupAgro, Montpellier, France
| | - Véronique Roussel
- CIRAD, UMR PHIM, Montpellier, France.,PHIM, Univ Montpellier, INRAe, CIRAD, Montpellier SupAgro, Montpellier, France
| | | | - Jaime Aguayo
- ANSES, Laboratoire de la Santé des Végétaux (LSV), Unité de Mycologie, Malzéville, France
| | - Catherine Abadie
- CIRAD, UMR PHIM, Montpellier, France.,PHIM, Univ Montpellier, INRAe, CIRAD, Montpellier SupAgro, Montpellier, France
| | - Jean Carlier
- CIRAD, UMR PHIM, Montpellier, France.,PHIM, Univ Montpellier, INRAe, CIRAD, Montpellier SupAgro, Montpellier, France
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11
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Impact of Host Resistance to Tomato Spotted Wilt Orthotospovirus in Peanut Cultivars on Virus Population Genetics and Thrips Fitness. Pathogens 2021; 10:pathogens10111418. [PMID: 34832574 PMCID: PMC8625697 DOI: 10.3390/pathogens10111418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/28/2021] [Accepted: 10/29/2021] [Indexed: 11/25/2022] Open
Abstract
Thrips-transmitted tomato spotted wilt orthotospovirus (TSWV) is a major constraint to peanut production in the southeastern United States. Peanut cultivars with resistance to TSWV have been widely used for over twenty years. Intensive usage of resistant cultivars has raised concerns about possible selection pressure against TSWV and a likelihood of resistance breakdown. Population genetics of TSWV isolates collected from cultivars with varying levels of TSWV resistance was investigated using five TSWV genes. Phylogenetic trees of genes did not indicate host resistance-based clustering of TSWV isolates. Genetic variation in TSWV isolates and neutrality tests suggested recent population expansion. Mutation and purifying selection seem to be the major forces driving TSWV evolution. Positive selection was found in N and RdRp genes but was not influenced by TSWV resistance. Population differentiation occurred between isolates collected from 1998 and 2010 and from 2016 to 2019 but not between isolates from susceptible and resistant cultivars. Evaluated TSWV-resistant cultivars differed, albeit not substantially, in their susceptibility to thrips. Thrips oviposition was reduced, and development was delayed in some cultivars. Overall, no evidence was found to support exertion of selection pressure on TSWV by host resistance in peanut cultivars, and some cultivars differentially affected thrips fitness than others.
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12
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Quillévéré-Hamard A, Le Roy G, Lesné A, Le May C, Pilet-Nayel ML. Aggressiveness of Diverse French Aphanomyces euteiches Isolates on Pea Near Isogenic Lines Differing in Resistance Quantitative Trait Loci. PHYTOPATHOLOGY 2021; 111:695-702. [PMID: 32781903 DOI: 10.1094/phyto-04-20-0147-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Aphanomyces root rot is a major disease in many pea growing regions worldwide. Development of resistant varieties is necessary to manage the disease. Near isogenic lines (NILs) carrying resistance alleles at main quantitative trait loci (QTLs) were developed by marker-assisted backcrossing. This study aimed to evaluate the aggressiveness of diverse French isolates of Aphanomyces euteiches on NILs carrying different resistance QTLs. Forty-three A. euteiches isolates from different French pea growing regions were tested for aggressiveness on eight NILs carrying single or combinations of resistance QTLs and two susceptible or resistant control lines, in controlled conditions. Three clusters of isolates, unrelated to geographical origin, were identified, including 37, 56, and 7% of isolates with high, moderate, and low average levels of aggressiveness, respectively. Three groups of pea lines were also identified. The first group consisted of a pea resistant control line, moderately to highly resistant to all of the isolates. The second group included five NILs carrying a major-effect resistance allele at QTL Ae-Ps7.6, with a medium to broad range of effects on the isolates. The third group consisted of three NILs carrying minor-effect resistance alleles, with a narrow range of effects on the isolates. The results suggest that highly aggressive isolates occur naturally, which may be selected by future partially resistant pea varieties carrying QTLs and increase the risk of erosion of QTL effect. QTL pyramiding strategies for a higher level and a broader range of effect of quantitative resistance on A. euteiches populations will be required for breeding for durable pea resistant varieties.
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Affiliation(s)
| | - Gwenola Le Roy
- IGEPP, INRAE, Institut Agro, Univ Rennes, 35653, Le Rheu, France
| | - Angélique Lesné
- IGEPP, INRAE, Institut Agro, Univ Rennes, 35653, Le Rheu, France
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13
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Rousseau E, Bonneault M, Fabre F, Moury B, Mailleret L, Grognard F. Virus epidemics, plant-controlled population bottlenecks and the durability of plant resistance. Philos Trans R Soc Lond B Biol Sci 2020; 374:20180263. [PMID: 31056046 DOI: 10.1098/rstb.2018.0263] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Plant qualitative resistances to viruses are natural exhaustible resources that can be impaired by the emergence of resistance-breaking (RB) virus variants. Mathematical modelling can help determine optimal strategies for resistance durability by a rational deployment of resistance in agroecosystems. Here, we propose an innovative approach, built up from our previous empirical studies, based on plant cultivars combining qualitative resistance with quantitative resistance narrowing population bottlenecks exerted on viruses during host-to-host transmission and/or within-host infection. Narrow bottlenecks are expected to slow down virus adaptation to plant qualitative resistance. To study the effect of bottleneck size on yield, we developed a stochastic epidemic model with mixtures of susceptible and resistant plants, relying on continuous-time Markov chain processes. Overall, narrow bottlenecks are beneficial when the fitness cost of RB virus variants in susceptible plants is intermediate. In such cases, they could provide up to 95 additional percentage points of yield compared with deploying a qualitative resistance alone. As we have shown in previous works that virus population bottlenecks are at least partly heritable plant traits, our results suggest that breeding and deploying plant varieties exposing virus populations to narrowed bottlenecks will increase yield and delay the emergence of RB variants. This article is part of the theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes'. This issue is linked with the subsequent theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control'.
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Affiliation(s)
- Elsa Rousseau
- 1 Université Côte d'Azur, Inria, INRA, CNRS, Sorbonne Université, Biocore team , Sophia Antipolis , France.,2 Université Côte d'Azur, INRA, CNRS, ISA , France.,3 Pathologie Végétale, INRA , F-84140 Montfavet , France
| | - Mélanie Bonneault
- 1 Université Côte d'Azur, Inria, INRA, CNRS, Sorbonne Université, Biocore team , Sophia Antipolis , France
| | - Frédéric Fabre
- 4 UMR 1065 SAVE, INRA , Bordeaux Sciences Agro, F-33882, Villenave d'Ornon , France
| | - Benoît Moury
- 3 Pathologie Végétale, INRA , F-84140 Montfavet , France
| | - Ludovic Mailleret
- 1 Université Côte d'Azur, Inria, INRA, CNRS, Sorbonne Université, Biocore team , Sophia Antipolis , France.,2 Université Côte d'Azur, INRA, CNRS, ISA , France
| | - Frédéric Grognard
- 1 Université Côte d'Azur, Inria, INRA, CNRS, Sorbonne Université, Biocore team , Sophia Antipolis , France
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14
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Cowger C, Brown JKM. Durability of Quantitative Resistance in Crops: Greater Than We Know? ANNUAL REVIEW OF PHYTOPATHOLOGY 2019; 57:253-277. [PMID: 31206351 DOI: 10.1146/annurev-phyto-082718-100016] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Quantitative resistance (QR) to crop diseases has usually been much more durable than major-gene, effector-triggered resistance. It has been observed that the effectiveness of some QR has eroded as pathogens adapt to it, especially when deployment is extensive and epidemics occur regularly, but it generally declines more slowly than effector-triggered resistance. Changes in aggressiveness and specificity of diverse pathogens on cultivars with QR have been recorded, along with experimental data on fitness costs of pathogen adaptation to QR, but there is little information about molecular mechanisms of adaptation. Some QR has correlated or antagonistic effects on multiple diseases. Longitudinal data on cultivars' disease ratings in trials over several years can be used to assess the significance of QR for durable resistance in crops. It is argued that published data likely underreport the durability of QR, owing to publication bias. The implications of research on QR for plant breeding are discussed.
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Affiliation(s)
- Christina Cowger
- USDA-ARS and North Carolina State University, Raleigh, North Carolina 27695, USA;
| | - James K M Brown
- Department of Crop Genetics, John Innes Centre, Colney, Norwich NR4 7UK, United Kingdom;
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15
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Huang X, Sun M, Lu X, Li S. Serial passage through resistant and susceptible cucumber cultivars affects the virulence of Fusarium oxysporum f. sp. cucumerinum. Microbiologyopen 2019; 8:e00641. [PMID: 29797483 PMCID: PMC6391263 DOI: 10.1002/mbo3.641] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/07/2018] [Accepted: 03/24/2018] [Indexed: 12/18/2022] Open
Abstract
Fusarium oxysporum f. sp. cucumerinum (Foc) is the causal pathogen of cucumber Fusarium wilt resulting in losses to cucumber production. To investigate the effects of the selective pressures of host plants on the virulence of Foc, a low virulence isolate, foc-3b, was successively inoculated on resistant and susceptible cucumber cultivars for five generations. The virulence of the original isolate diverged; virulence was significantly strengthened after serial passage on the resistant cultivar and weakened on the susceptible plants (p ˂ .05). The expression of four virulence-related genes of F. oxysporum, G-protein α subunit gene fga1, sucrose nonfermenting 1 gene snf1, F-box protein gene frp1, and Class V chitin synthase gene chsV, was quantified using real-time PCR. All genes were significantly upregulated after serial passage on the resistant cultivar, compared to the original strain, and the expression of snf1 was downregulated in strains re-isolated from the susceptible plants (p ˂ .05). A significant positive correlation was found between the expression levels of gene snf1, frp1, and chsV and disease severity of cucumber Fusarium wilt, suggesting these genes may impact virulence differentiation. This study will improve the management of cucumber Fusarium wilt and provide insight into the mechanisms underlying virulence of F. oxysporum.
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Affiliation(s)
- Xiaoqing Huang
- Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Manhong Sun
- Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Xiaohong Lu
- Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
| | - Shidong Li
- Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina
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16
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Bera S, Fraile A, García-Arenal F. Analysis of Fitness Trade-Offs in the Host Range Expansion of an RNA Virus, Tobacco Mild Green Mosaic Virus. J Virol 2018; 92:e01268-18. [PMID: 30257999 PMCID: PMC6258955 DOI: 10.1128/jvi.01268-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/13/2018] [Indexed: 12/14/2022] Open
Abstract
The acquisition of new hosts provides a virus with more opportunities for transmission and survival but may be limited by across-host fitness trade-offs. Major causes of across-host trade-offs are antagonistic pleiotropy, that is, host differential phenotypic effects of mutations, a Genotype x Environment interaction, and epistasis, a Genotype x Genotype interaction. Here, we analyze if there are trade-offs, and what are the causes, associated with the acquisition by tobacco mild green mosaic virus (TMGMV) of a new host. For this, the multiplication of sympatric field isolates of TMGMV from its wild reservoir host Nicotiana glauca and from pepper crops was quantified in the original and the heterologous hosts. TMGMV isolates from N. glauca were adapted to their host, but pepper isolates were not adapted to pepper, and the acquisition of this new host was associated with a fitness penalty in the original host. Analyses of the collection of field isolates and of mutant genotypes derived from biologically active cDNA clones showed a role of mutations in the coat protein and the 3' untranslated region in determining within-host virus fitness. Fitness depended on host-specific effects of these mutations, on the genetic background in which they occurred, and on higher-order interactions of the type Genotype x Genotype x Environment. These types of effects had been reported to generate across-host fitness trade-offs under experimental evolution. Our results show they may also operate in heterogeneous natural environments and could explain why pepper isolates were not adapted to pepper and their lower fitness in N. glaucaIMPORTANCE The acquisition of new hosts conditions virus epidemiology and emergence; hence it is important to understand the mechanisms behind host range expansion. Experimental evolution studies have identified antagonistic pleiotropy and epistasis as genetic mechanisms that limit host range expansion, but studies from virus field populations are few. Here, we compare the performance of isolates of tobacco mild green mosaic virus from its reservoir host, Nicotiana glauca, and its new host, pepper, showing that acquisition of a new host was not followed by adaptation to it but was associated with a fitness loss in the original host. Analysis of mutations determining host-specific virus multiplication identified antagonistic pleiotropy, epistasis, and host-specific epistasis as mechanisms generating across-host fitness trade-offs that may prevent adaptation to pepper and cause a loss of fitness in N. glauca Thus, mechanisms determining trade-offs, identified under experimental evolution, could also operate in the heterogeneous environment in which natural plant virus populations occur.
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Affiliation(s)
- Sayanta Bera
- Centro de Biotecnología y Genómica de Plantas UPM-INIA and E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
| | - Aurora Fraile
- Centro de Biotecnología y Genómica de Plantas UPM-INIA and E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
| | - Fernando García-Arenal
- Centro de Biotecnología y Genómica de Plantas UPM-INIA and E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
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17
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Papaïx J, Rimbaud L, Burdon JJ, Zhan J, Thrall PH. Differential impact of landscape-scale strategies for crop cultivar deployment on disease dynamics, resistance durability and long-term evolutionary control. Evol Appl 2018; 11:705-717. [PMID: 29875812 PMCID: PMC5979631 DOI: 10.1111/eva.12570] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 10/23/2017] [Indexed: 01/28/2023] Open
Abstract
A multitude of resistance deployment strategies have been proposed to tackle the evolutionary potential of pathogens to overcome plant resistance. In particular, many landscape-based strategies rely on the deployment of resistant and susceptible cultivars in an agricultural landscape as a mosaic. However, the design of such strategies is not easy as strategies targeting epidemiological or evolutionary outcomes may not be the same. Using a stochastic spatially explicit model, we studied the impact of landscape organization (as defined by the proportion of fields cultivated with a resistant cultivar and their spatial aggregation) and key pathogen life-history traits on three measures of disease control. Our results show that short-term epidemiological dynamics are optimized when landscapes are planted with a high proportion of the resistant cultivar in low aggregation. Importantly, the exact opposite situation is optimal for resistance durability. Finally, well-mixed landscapes (balanced proportions with low aggregation) are optimal for long-term evolutionary equilibrium (defined here as the level of long-term pathogen adaptation). This work offers a perspective on the potential for contrasting effects of landscape organization on different goals of disease management and highlights the role of pathogen life history.
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Affiliation(s)
| | | | | | - Jiasui Zhan
- Fujian Key Laboratory of Plant VirologyInstitute of Plant VirologyFujian Agriculture and Forestry UniversityFuzhouChina
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18
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Jeger MJ, Madden LV, van den Bosch F. Plant Virus Epidemiology: Applications and Prospects for Mathematical Modeling and Analysis to Improve Understanding and Disease Control. PLANT DISEASE 2018; 102:837-854. [PMID: 30673389 DOI: 10.1094/pdis-04-17-0612-fe] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
In recent years, mathematical modeling has increasingly been used to complement experimental and observational studies of biological phenomena across different levels of organization. In this article, we consider the contribution of mathematical models developed using a wide range of techniques and uses to the study of plant virus disease epidemics. Our emphasis is on the extent to which models have contributed to answering biological questions and indeed raised questions related to the epidemiology and ecology of plant viruses and the diseases caused. In some cases, models have led to direct applications in disease control, but arguably their impact is better judged through their influence in guiding research direction and improving understanding across the characteristic spatiotemporal scales of plant virus epidemics. We restrict this article to plant virus diseases for reasons of length and to maintain focus even though we recognize that modeling has played a major and perhaps greater part in the epidemiology of other plant pathogen taxa, including vector-borne bacteria and phytoplasmas.
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Affiliation(s)
- M J Jeger
- Centre for Environmental Policy, Imperial College London, Silwood Park, Ascot SL5 7PY, United Kingdom
| | - L V Madden
- Department of Plant Pathology, Ohio State University, Wooster, OH 44691
| | - F van den Bosch
- Computational and Systems Biology, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom
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19
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McLeish MJ, Fraile A, García-Arenal F. Ecological Complexity in Plant Virus Host Range Evolution. Adv Virus Res 2018; 101:293-339. [PMID: 29908592 DOI: 10.1016/bs.aivir.2018.02.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The host range of a plant virus is the number of species in which it can reproduce. Most studies of plant virus host range evolution have focused on the genetics of host-pathogen interactions. However, the distribution and abundance of plant viruses and their hosts do not always overlap, and these spatial and temporal discontinuities in plant virus-host interactions can result in various ecological processes that shape host range evolution. Recent work shows that the distributions of pathogenic and resistant genotypes, vectors, and other resources supporting transmission vary widely in the environment, producing both expected and unanticipated patterns. The distributions of all of these factors are influenced further by competitive effects, natural enemies, anthropogenic disturbance, the abiotic environment, and herbivory to mention some. We suggest the need for further development of approaches that (i) explicitly consider resource use and the abiotic and biotic factors that affect the strategies by which viruses exploit resources; and (ii) are sensitive across scales. Host range and habitat specificity will largely determine which phyla are most likely to be new hosts, but predicting which host and when it is likely to be infected is enormously challenging because it is unclear how environmental heterogeneity affects the interactions of viruses and hosts.
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Affiliation(s)
- Michael J McLeish
- Centro de Biotecnología y Genómica de Plantas UPM-INIA, and E.T.S.I. Agrícola, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Madrid, Spain
| | - Aurora Fraile
- Centro de Biotecnología y Genómica de Plantas UPM-INIA, and E.T.S.I. Agrícola, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Madrid, Spain
| | - Fernando García-Arenal
- Centro de Biotecnología y Genómica de Plantas UPM-INIA, and E.T.S.I. Agrícola, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Madrid, Spain.
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20
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Rimbaud L, Papaïx J, Rey JF, Barrett LG, Thrall PH. Assessing the durability and efficiency of landscape-based strategies to deploy plant resistance to pathogens. PLoS Comput Biol 2018; 14:e1006067. [PMID: 29649208 PMCID: PMC5918245 DOI: 10.1371/journal.pcbi.1006067] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 04/24/2018] [Accepted: 02/27/2018] [Indexed: 11/18/2022] Open
Abstract
Genetically-controlled plant resistance can reduce the damage caused by pathogens. However, pathogens have the ability to evolve and overcome such resistance. This often occurs quickly after resistance is deployed, resulting in significant crop losses and a continuing need to develop new resistant cultivars. To tackle this issue, several strategies have been proposed to constrain the evolution of pathogen populations and thus increase genetic resistance durability. These strategies mainly rely on varying different combinations of resistance sources across time (crop rotations) and space. The spatial scale of deployment can vary from multiple resistance sources occurring in a single cultivar (pyramiding), in different cultivars within the same field (cultivar mixtures) or in different fields (mosaics). However, experimental comparison of the efficiency (i.e. ability to reduce disease impact) and durability (i.e. ability to limit pathogen evolution and delay resistance breakdown) of landscape-scale deployment strategies presents major logistical challenges. Therefore, we developed a spatially explicit stochastic model able to assess the epidemiological and evolutionary outcomes of the four major deployment options described above, including both qualitative resistance (i.e. major genes) and quantitative resistance traits against several components of pathogen aggressiveness: infection rate, latent period duration, propagule production rate, and infectious period duration. This model, implemented in the R package landsepi, provides a new and useful tool to assess the performance of a wide range of deployment options, and helps investigate the effect of landscape, epidemiological and evolutionary parameters. This article describes the model and its parameterisation for rust diseases of cereal crops, caused by fungi of the genus Puccinia. To illustrate the model, we use it to assess the epidemiological and evolutionary potential of the combination of a major gene and different traits of quantitative resistance. The comparison of the four major deployment strategies described above will be the objective of future studies. There are many recent examples which demonstrate the evolutionary potential of plant pathogens to overcome the resistances deployed in agricultural landscapes to protect our crops. Increasingly, it is recognised that how resistance is deployed spatially and temporally can impact on rates of pathogen evolution and resistance breakdown. Such deployment strategies are mainly based on the combination of several sources of resistance at different spatiotemporal scales. However, comparison of these strategies in a predictive sense is not an easy task, owing to the logistical difficulties associated with experiments involving the spread of a pathogen at large spatio-temporal scales. Moreover, both the durability of a strategy and the epidemiological protection it provides to crops must be assessed since these evaluation criteria are not necessarily correlated. Surprisingly, no current simulation model allows a thorough comparison of the different options. Here we describe a spatio-temporal model able to simulate a wide range of deployment strategies and resistance sources. This model, implemented in the R package landsepi, facilitates assessment of both epidemiological and evolutionary outcomes across simulated scenarios. In this work, the model is used to investigate the combination of different sources of resistance against fungal diseases such as rusts of cereal crops.
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Affiliation(s)
- Loup Rimbaud
- CSIRO Agriculture and Food, Canberra, ACT, Australia
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21
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McCorkle KL, Drake-Stowe K, Lewis RS, Shew D. Characterization of Phytophthora nicotianae Resistance Conferred by the Introgressed Nicotiana rustica Region, Wz, in Flue-Cured Tobacco. PLANT DISEASE 2018; 102:309-317. [PMID: 30673528 DOI: 10.1094/pdis-03-17-0339-re] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Black shank, caused by Phytophthora nicotianae, is one of the most important diseases affecting tobacco worldwide and is primarily managed through use of host resistance. An additional source of resistance to P. nicotianae, designated as Wz, has been introgressed into Nicotiana tabacum from N. rustica. The Wz gene region confers high levels of resistance to all races, but has not been characterized. Our study found Wz-mediated resistance is most highly expressed in the roots, with only a slight reduction in stem-lesion size in Wz genotypes compared with susceptible controls. No substantial relationships were observed between initial inoculum levels and disease development on Wz genotypes, which is generally consistent with qualitative or complete resistance. Isolates of P. nicotianae adapted for five host generations on plants with the Wz gene caused higher disease severity than isolates adapted on Wz plants for only one host generation. Wz-adapted isolates did not exhibit increased aggressiveness on genotypes with other sources of partial resistance, suggesting pathogen adaptation was specific to the Wz gene. To reduce potential for pathogen population shifts with virulence on Wz genotypes, Wz should be combined with other resistance sources and rotation of varying black shank resistance mechanisms is also recommended.
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Affiliation(s)
- Kestrel L McCorkle
- Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695
| | - Katherine Drake-Stowe
- Department of Crop and Soil Science, North Carolina State University, Raleigh, NC 27695
| | - Ramsey S Lewis
- Department of Crop and Soil Science, North Carolina State University, Raleigh, NC 27695
| | - David Shew
- Department of Plant Pathology, North Carolina State University, Raleigh, NC
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22
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Wininger K, Rank N. Evolutionary dynamics of interactions between plants and their enemies: comparison of herbivorous insects and pathogens. Ann N Y Acad Sci 2017; 1408:46-60. [PMID: 29125186 DOI: 10.1111/nyas.13541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 09/29/2017] [Accepted: 10/04/2017] [Indexed: 01/21/2023]
Abstract
Plants colonized land over 400 million years ago. Shortly thereafter, organisms began to consume terrestrial plant tissue as a nutritional resource. Most plant enemies are plant pathogens or herbivores, and they impose natural selection for plants to evolve defenses. These traits generate selection pressures on enemies. Coevolution between terrestrial plants and their enemies is an important element of the evolutionary history of both groups. However, coevolutionary studies of plant-pathogen interactions have tended to focus on different research topics than plant-herbivore interactions. Specifically, studies of plant-pathogen interactions often adopt a "gene-for-gene" conceptual framework. In contrast, studies of plants and herbivores often investigate escalation or elaboration of plant defense and herbivore adaptations to overcome it. The main exceptions to the general pattern are studies that focus on small, sessile herbivores that share many features with plant pathogens, studies that incorporate both herbivores and pathogens into a single investigation, and studies that test aspects of Thompson's geographic mosaic theory for coevolution. We discuss the implications of these findings for future research.
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Affiliation(s)
- Kerry Wininger
- Department of Biology, Sonoma State University, Rohnert Park, California
| | - Nathan Rank
- Department of Biology, Sonoma State University, Rohnert Park, California
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23
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Pilet-Nayel ML, Moury B, Caffier V, Montarry J, Kerlan MC, Fournet S, Durel CE, Delourme R. Quantitative Resistance to Plant Pathogens in Pyramiding Strategies for Durable Crop Protection. FRONTIERS IN PLANT SCIENCE 2017; 8:1838. [PMID: 29163575 PMCID: PMC5664368 DOI: 10.3389/fpls.2017.01838] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 10/10/2017] [Indexed: 05/18/2023]
Abstract
Quantitative resistance has gained interest in plant breeding for pathogen control in low-input cropping systems. Although quantitative resistance frequently has only a partial effect and is difficult to select, it is considered more durable than major resistance (R) genes. With the exponential development of molecular markers over the past 20 years, resistance QTL have been more accurately detected and better integrated into breeding strategies for resistant varieties with increased potential for durability. This review summarizes current knowledge on the genetic inheritance, molecular basis, and durability of quantitative resistance. Based on this knowledge, we discuss how strategies that combine major R genes and QTL in crops can maintain the effectiveness of plant resistance to pathogens. Combining resistance QTL with complementary modes of action appears to be an interesting strategy for breeding effective and potentially durable resistance. Combining quantitative resistance with major R genes has proven to be a valuable approach for extending the effectiveness of major genes. In the plant genomics era, improved tools and methods are becoming available to better integrate quantitative resistance into breeding strategies. Nevertheless, optimal combinations of resistance loci will still have to be identified to preserve resistance effectiveness over time for durable crop protection.
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Affiliation(s)
- Marie-Laure Pilet-Nayel
- Institute for Genetics, Environment and Plant Protection (INRA), UMR 1349, Leu Rheu, France
- PISOM, UMT INRA-Terres Inovia, Le Rheu, France
| | | | - Valérie Caffier
- Research Institute of Horticulture and Seeds (INRA), UMR 1345, Beaucouzé, France
| | - Josselin Montarry
- Institute for Genetics, Environment and Plant Protection (INRA), UMR 1349, Leu Rheu, France
| | - Marie-Claire Kerlan
- Institute for Genetics, Environment and Plant Protection (INRA), UMR 1349, Leu Rheu, France
| | - Sylvain Fournet
- Institute for Genetics, Environment and Plant Protection (INRA), UMR 1349, Leu Rheu, France
| | - Charles-Eric Durel
- Research Institute of Horticulture and Seeds (INRA), UMR 1345, Beaucouzé, France
| | - Régine Delourme
- Institute for Genetics, Environment and Plant Protection (INRA), UMR 1349, Leu Rheu, France
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24
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Bera S, Moreno-Pérez MG, García-Figuera S, Pagán I, Fraile A, Pacios LF, García-Arenal F. Pleiotropic Effects of Resistance-Breaking Mutations on Particle Stability Provide Insight into Life History Evolution of a Plant RNA Virus. J Virol 2017; 91:e00435-17. [PMID: 28679755 PMCID: PMC5571237 DOI: 10.1128/jvi.00435-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 06/27/2017] [Indexed: 11/20/2022] Open
Abstract
In gene-for-gene host-virus interactions, virus evolution to infect and multiply in previously resistant host genotypes, i.e., resistance breaking, is a case of host range expansion, which is predicted to be associated with fitness penalties. Negative effects of resistance-breaking mutations on within-host virus multiplication have been documented for several plant viruses. However, understanding virus evolution requires analyses of potential trade-offs between different fitness components. Here we analyzed whether coat protein (CP) mutations in Pepper mild mottle virus that break L-gene resistance in pepper affect particle stability and, thus, survival in the environment. For this purpose, CP mutations determining the overcoming of L 3 and L 4 resistance alleles were introduced in biologically active cDNA clones. The kinetics of the in vitro disassembly of parental and mutant particles were compared under different conditions. Resistance-breaking mutations variously affected particle stability. Structural analyses identified the number and type of axial and side interactions of adjacent CP subunits in virions, which explained differences in particle stability and contribute to understanding of tobamovirus disassembly. Resistance-breaking mutations also affected virus multiplication and virulence in the susceptible host, as well as infectivity. The sense and magnitude of the effects of resistance-breaking mutations on particle stability, multiplication, virulence, or infectivity depended on the specific mutation rather than on the ability to overcome the different resistance alleles, and effects on different traits were not correlated. Thus, the results do not provide evidence of links or trade-offs between particle stability, i.e., survival, and other components of virus fitness or virulence.IMPORTANCE The effect of survival on virus evolution remains underexplored, despite the fact that life history trade-offs may constrain virus evolution. We approached this topic by analyzing whether breaking of L-gene resistance in pepper by Pepper mild mottle virus, determined by coat protein (CP) mutations, is associated with reduced particle stability and survival. Resistance-breaking mutations affected particle stability by altering the interactions between CP subunits. However, the sense and magnitude of these effects were unrelated to the capacity to overcome different resistance alleles. Thus, resistance breaking was not traded with survival. Resistance-breaking mutations also affected virus fitness within the infected host, virulence, and infectivity in a mutation-specific manner. Comparison of the effects of CP mutations on these various traits indicates that there are neither trade-offs nor positive links between survival and other life history traits. These results demonstrate that trade-offs between life history traits may not be a general constraint in virus evolution.
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Affiliation(s)
- Sayanta Bera
- Centro de Biotecnología y Genómica de Plantas and Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
| | - Manuel G Moreno-Pérez
- Centro de Biotecnología y Genómica de Plantas and Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
| | - Sara García-Figuera
- Centro de Biotecnología y Genómica de Plantas and Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
| | - Israel Pagán
- Centro de Biotecnología y Genómica de Plantas and Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
| | - Aurora Fraile
- Centro de Biotecnología y Genómica de Plantas and Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
| | - Luis F Pacios
- Centro de Biotecnología y Genómica de Plantas and Escuela Técnica Superior de Ingenieros de Montes, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
| | - Fernando García-Arenal
- Centro de Biotecnología y Genómica de Plantas and Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
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Pinel-Galzi A, Dubreuil-Tranchant C, Hébrard E, Mariac C, Ghesquière A, Albar L. Mutations in Rice yellow mottle virus Polyprotein P2a Involved in RYMV2 Gene Resistance Breakdown. FRONTIERS IN PLANT SCIENCE 2016; 7:1779. [PMID: 27965688 PMCID: PMC5125353 DOI: 10.3389/fpls.2016.01779] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 11/11/2016] [Indexed: 05/09/2023]
Abstract
Rice yellow mottle virus (RYMV) is one of the major diseases of rice in Africa. The high resistance of the Oryza glaberrima Tog7291 accession involves a null allele of the RYMV2 gene, whose ortholog in Arabidopsis, CPR5, is a transmembrane nucleoporin involved in effector-triggered immunity. To optimize field deployment of the RYMV2 gene and improve its durability, which is often a weak point in varietal resistance, we analyzed its efficiency toward RYMV isolates representing the genetic diversity of the virus and the molecular basis of resistance breakdown. Tog7291 resistance efficiency was highly variable depending on the isolate used, with infection rates ranging from 0 to 98% of plants. Back-inoculation experiments indicated that infection cases were not due to an incomplete resistance phenotype but to the emergence of resistance-breaking (RB) variants. Interestingly, the capacity of the virus to overcome Tog7291 resistance is associated with a polymorphism at amino-acid 49 of the VPg protein which also affects capacity to overcome the previously studied RYMV1 resistance gene. This polymorphism appeared to be a main determinant of the emergence of RB variants. It acts independently of the resistance gene and rather reflects inter-species adaptation with potential consequences for the durability of resistance. RB mutations were identified by full-length or partial sequencing of the RYMV genome in infected Tog7291 plants and were validated by directed mutagenesis of an infectious viral clone. We found that Tog7291 resistance breakdown involved mutations in the putative membrane anchor domain of the polyprotein P2a. Although the precise effect of these mutations on rice/RYMV interaction is still unknown, our results offer a new perspective for the understanding of RYMV2 mediated resistance mechanisms. Interestingly, in the susceptible IR64 variety, RB variants showed low infectivity and frequent reversion to the wild-type genotype, suggesting that Tog7291 resistance breakdown is associated with a major loss of viral fitness in normally susceptible O. sativa varieties. Despite the high frequency of resistance breakdown in controlled conditions, this loss of fitness is an encouraging element with regards to RYMV2 resistance durability.
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Affiliation(s)
- Agnès Pinel-Galzi
- Interactions Plantes Microorganismes Environnement, Institut de Recherche pour le Développement – Centre de Coopération Internationale en Recherche Agronomique pour le Développement – Université de MontpellierMontpellier, France
| | - Christine Dubreuil-Tranchant
- Plant Diversity Adaptation and Development Research Unit, Institut de Recherche pour le Développement – Université de MontpellierMontpellier, France
| | - Eugénie Hébrard
- Interactions Plantes Microorganismes Environnement, Institut de Recherche pour le Développement – Centre de Coopération Internationale en Recherche Agronomique pour le Développement – Université de MontpellierMontpellier, France
| | - Cédric Mariac
- Plant Diversity Adaptation and Development Research Unit, Institut de Recherche pour le Développement – Université de MontpellierMontpellier, France
| | - Alain Ghesquière
- Plant Diversity Adaptation and Development Research Unit, Institut de Recherche pour le Développement – Université de MontpellierMontpellier, France
| | - Laurence Albar
- Plant Diversity Adaptation and Development Research Unit, Institut de Recherche pour le Développement – Université de MontpellierMontpellier, France
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Moreno-Pérez MG, García-Luque I, Fraile A, García-Arenal F. Mutations That Determine Resistance Breaking in a Plant RNA Virus Have Pleiotropic Effects on Its Fitness That Depend on the Host Environment and on the Type, Single or Mixed, of Infection. J Virol 2016; 90:9128-37. [PMID: 27489266 PMCID: PMC5044817 DOI: 10.1128/jvi.00737-16] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 07/25/2016] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED Overcoming host resistance in gene-for-gene host-virus interactions is an important instance of host range expansion, which can be hindered by across-host fitness trade-offs. Trade-offs are generated by negative effects of host range mutations on the virus fitness in the original host, i.e., by antagonistic pleiotropy. It has been reported that different mutations in Pepper mild mottle virus (PMMoV) coat protein result in overcoming L-gene resistance in pepper. To analyze if resistance-breaking mutations in PMMoV result in antagonistic pleiotropy, all reported mutations determining the overcoming of L(3) and L(4) alleles were introduced in biologically active cDNA clones. Then, the parental and mutant virus genotypes were assayed in susceptible pepper genotypes with an L(+), L(1), or L(2) allele, in single and in mixed infections. Resistance-breaking mutations had pleiotropic effects on the virus fitness that, according to the specific mutation, the host genotype, and the type of infection, single or mixed with other virus genotypes, were antagonistic or positive. Thus, resistance-breaking mutations can generate fitness trade-offs both across hosts and across types of infection, and the frequency of host range mutants will depend on the genetic structure of the host population and on the frequency of mixed infections by different virus genotypes. Also, resistance-breaking mutations variously affected virulence, which may further influence the evolution of host range expansion. IMPORTANCE A major cause of virus emergence is host range expansion, which may be hindered by across-host fitness trade-offs caused by negative pleiotropy of host range mutations. An important instance of host range expansion is overcoming host resistance in gene-for-gene plant-virus interactions. We analyze here if mutations in the coat protein of Pepper mild mottle virus determining L-gene resistance-breaking in pepper have associated fitness penalties in susceptible host genotypes. Results show that pleiotropic effects of resistance-breaking mutations on virus fitness depend on the specific mutation, the susceptible host genotype, and the type of infection, single or mixed, with other virus genotypes. Accordingly, resistance-breaking mutations can have negative, positive, or no pleiotropic effects on virus fitness. These results underscore the complexity of host range expansion evolution and, specifically, the difficulty of predicting the overcoming of resistance factors in crops.
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Affiliation(s)
- Manuel G Moreno-Pérez
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA) and E.T.S.I. Agrónomos, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
| | | | - Aurora Fraile
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA) and E.T.S.I. Agrónomos, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
| | - Fernando García-Arenal
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA) and E.T.S.I. Agrónomos, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
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27
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Fournet S, Eoche-Bosy D, Renault L, Hamelin FM, Montarry J. Adaptation to resistant hosts increases fitness on susceptible hosts in the plant parasitic nematode Globodera pallida. Ecol Evol 2016; 6:2559-68. [PMID: 27066239 PMCID: PMC4797161 DOI: 10.1002/ece3.2079] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 01/28/2016] [Accepted: 02/09/2016] [Indexed: 12/30/2022] Open
Abstract
Trade-offs between virulence (defined as the ability to infect a resistant host) and life-history traits are of particular interest in plant pathogens for durable management of plant resistances. Adaptation to plant resistances (i.e., virulence acquisition) is indeed expected to be associated with a fitness cost on susceptible hosts. Here, we investigated whether life-history traits involved in the fitness of the potato cyst nematode Globodera pallida are affected in a virulent lineage compared to an avirulent one. Both lineages were obtained from the same natural population through experimental evolution on resistant and susceptible hosts, respectively. Unexpectedly, we found that virulent lineages were more fit than avirulent lineages on susceptible hosts: they produced bigger cysts, containing more larvae and hatching faster. We thus discuss possible reasons explaining why virulence did not spread into natural G. pallida populations.
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Affiliation(s)
- Sylvain Fournet
- INRA UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection) F-35653 Le Rheu France
| | - Delphine Eoche-Bosy
- INRA UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection) F-35653 Le Rheu France
| | - Lionel Renault
- INRA UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection) F-35653 Le Rheu France
| | - Frédéric M Hamelin
- INRA UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection) F-35653 Le Rheu France
| | - Josselin Montarry
- INRA UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection) F-35653 Le Rheu France
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Delmas CEL, Fabre F, Jolivet J, Mazet ID, Richart Cervera S, Delière L, Delmotte F. Adaptation of a plant pathogen to partial host resistance: selection for greater aggressiveness in grapevine downy mildew. Evol Appl 2016; 9:709-25. [PMID: 27247621 PMCID: PMC4869412 DOI: 10.1111/eva.12368] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 01/27/2016] [Indexed: 01/29/2023] Open
Abstract
An understanding of the evolution of pathogen quantitative traits in response to host selective pressures is essential for the development of durable management strategies for resistant crops. However, we still lack experimental data on the effects of partial host resistance on multiple phenotypic traits (aggressiveness) and evolutionary strategies in pathogens. We performed a cross‐inoculation experiment with four grapevine hosts and 103 isolates of grapevine downy mildew (Plasmopara viticola) sampled from susceptible and partially resistant grapevine varieties. We analysed the neutral and adaptive genetic differentiation of five quantitative traits relating to pathogen transmission. Isolates from resistant hosts were more aggressive than isolates from susceptible hosts, as they had a shorter latency period and higher levels of spore production. This pattern of adaptation contrasted with the lack of neutral genetic differentiation, providing evidence for directional selection. No specificity for a particular host variety was detected. Adapted isolates had traits that were advantageous on all resistant varieties. There was no fitness cost associated with this genetic adaptation, but several trade‐offs between pathogen traits were observed. These results should improve the accuracy of prediction of fitness trajectories for this biotrophic pathogen, an essential element for the modelling of durable deployment strategies for resistant varieties.
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Affiliation(s)
- Chloé E L Delmas
- UMR 1065 Santé et Agroécologie du VignobleINRAVillenave d'OrnonFrance; Bordeaux Science AgroUMR 1065 SAVEISVVUniversité de BordeauxVillenave d'OrnonFrance
| | - Frédéric Fabre
- UMR 1065 Santé et Agroécologie du VignobleINRAVillenave d'OrnonFrance; Bordeaux Science AgroUMR 1065 SAVEISVVUniversité de BordeauxVillenave d'OrnonFrance
| | - Jérôme Jolivet
- UMR 1065 Santé et Agroécologie du VignobleINRAVillenave d'OrnonFrance; Bordeaux Science AgroUMR 1065 SAVEISVVUniversité de BordeauxVillenave d'OrnonFrance
| | - Isabelle D Mazet
- UMR 1065 Santé et Agroécologie du VignobleINRAVillenave d'OrnonFrance; Bordeaux Science AgroUMR 1065 SAVEISVVUniversité de BordeauxVillenave d'OrnonFrance
| | - Sylvie Richart Cervera
- UMR 1065 Santé et Agroécologie du VignobleINRAVillenave d'OrnonFrance; Bordeaux Science AgroUMR 1065 SAVEISVVUniversité de BordeauxVillenave d'OrnonFrance
| | - Laurent Delière
- UMR 1065 Santé et Agroécologie du VignobleINRAVillenave d'OrnonFrance; Bordeaux Science AgroUMR 1065 SAVEISVVUniversité de BordeauxVillenave d'OrnonFrance
| | - François Delmotte
- UMR 1065 Santé et Agroécologie du VignobleINRAVillenave d'OrnonFrance; Bordeaux Science AgroUMR 1065 SAVEISVVUniversité de BordeauxVillenave d'OrnonFrance
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Pasco C, Montarry J, Marquer B, Andrivon D. And the nasty ones lose in the end: foliar pathogenicity trades off with asexual transmission in the Irish famine pathogen Phytophthora infestans. THE NEW PHYTOLOGIST 2016; 209:334-342. [PMID: 26295446 DOI: 10.1111/nph.13581] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 06/26/2015] [Indexed: 06/04/2023]
Abstract
A trade-off between pathogenicity and transmission is often postulated to explain the persistence of pathogens over time. If demonstrated, it would help to predict the evolution of pathogenicity across cropping seasons, and to develop sustainable control strategies from this prediction. Unfortunately, experimental demonstration of such trade-offs in agricultural plant pathogens remains elusive. We measured asexual transmission of Phytophthora infestans isolates differing in pathogenicity in two sets of artificial infection experiments under controlled, semi-outdoor conditions. Higher foliar pathogenicity decreased mean daughter tuber weight, increased infection severity in daughter tubers, and increased stem mortality before emergence. The most pathogenic isolates thus suffer a double penalty for asexual transmission: a lower survival probability within small and severely infected tubers; and a lower infection probability of neighbouring healthy plants due to fewer infected stems produced by surviving tubers. Moderate tuber resistance favoured transmission of the least pathogenic isolates, while high levels of resistance almost abolished transmission of all isolates. These data demonstrate a trade-off between foliar pathogenicity and asexual transmission over seasons in P. infestans, which should stabilise pathogenicity over time in the potato late blight pathosystem and possibly favour clone replacement by less pathogenic lineages after demographic bottlenecks.
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Affiliation(s)
- Claudine Pasco
- UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection), INRA, Domaine de la Motte, BP 35327, Le Rheu Cedex, F-35653, France
| | - Josselin Montarry
- UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection), INRA, Domaine de la Motte, BP 35327, Le Rheu Cedex, F-35653, France
| | - Bruno Marquer
- UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection), INRA, Domaine de la Motte, BP 35327, Le Rheu Cedex, F-35653, France
| | - Didier Andrivon
- UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection), INRA, Domaine de la Motte, BP 35327, Le Rheu Cedex, F-35653, France
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30
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Rafaluk C, Jansen G, Schulenburg H, Joop G. When experimental selection for virulence leads to loss of virulence. Trends Parasitol 2015; 31:426-34. [DOI: 10.1016/j.pt.2015.06.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Revised: 06/01/2015] [Accepted: 06/15/2015] [Indexed: 11/30/2022]
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Zhan J, Thrall PH, Papaïx J, Xie L, Burdon JJ. Playing on a pathogen's weakness: using evolution to guide sustainable plant disease control strategies. ANNUAL REVIEW OF PHYTOPATHOLOGY 2015; 53:19-43. [PMID: 25938275 DOI: 10.1146/annurev-phyto-080614-120040] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Wild plants and their associated pathogens are involved in ongoing interactions over millennia that have been modified by coevolutionary processes to limit the spatial extent and temporal duration of disease epidemics. These interactions are disrupted by modern agricultural practices and social activities, such as intensified monoculture using superior varieties and international trading of agricultural commodities. These activities, when supplemented with high resource inputs and the broad application of agrochemicals, create conditions uniquely conducive to widespread plant disease epidemics and rapid pathogen evolution. To be effective and durable, sustainable disease management requires a significant shift in emphasis to overtly include ecoevolutionary principles in the design of adaptive management programs aimed at minimizing the evolutionary potential of plant pathogens by reducing their genetic variation, stabilizing their evolutionary dynamics, and preventing dissemination of pathogen variants carrying new infectivity or resistance to agrochemicals.
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Affiliation(s)
- Jiasui Zhan
- Key Laboratory for Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, 350002, China;
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Burdon JJ, Barrett LG, Rebetzke G, Thrall PH. Guiding deployment of resistance in cereals using evolutionary principles. Evol Appl 2014; 7:609-24. [PMID: 25067946 PMCID: PMC4105914 DOI: 10.1111/eva.12175] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 05/14/2014] [Indexed: 11/28/2022] Open
Abstract
Genetically controlled resistance provides plant breeders with an efficient means of controlling plant disease, but this approach has been constrained by practical difficulties associated with combining many resistance genes together and strong evolutionary responses from pathogen populations leading to subsequent resistance breakdown. However, continuing advances in molecular marker technologies are revolutionizing the ability to rapidly and reliably manipulate resistances of all types - major gene, adult plant and quantitative resistance loci singly or multiply into individual host lines. Here, we argue that these advances provide major opportunities to deliberately design deployment strategies in cereals that can take advantage of the evolutionary pressures faced by target pathogens. Different combinations of genes deployed either within single host individuals or between different individuals within or among crops, can be used to reduce the size of pathogen populations and generate patterns of disruptive selection. This will simultaneously limit immediate epidemic development and reduce the probability of subsequent evolutionary change in the pathogen for broader infectivity or increased aggressiveness. The same general principles are relevant to the control of noncereal diseases, but the most efficacious controls will vary reflecting the range of genetic options available and their fit with specific ecology and life-history combinations.
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Affiliation(s)
- Jeremy J Burdon
- CSIRO, Plant Industry Canberra, ACT, Australia ; CSIRO Biosecurity Flagship Canberra, ACT, Australia
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33
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Fraile A, Hily JM, Pagán I, Pacios LF, García-Arenal F. Host resistance selects for traits unrelated to resistance-breaking that affect fitness in a plant virus. Mol Biol Evol 2014; 31:928-39. [PMID: 24441034 DOI: 10.1093/molbev/msu045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
The acquisition by parasites of the capacity to infect resistant host genotypes, that is, resistance-breaking, is predicted to be hindered by across-host fitness trade-offs. All analyses of costs of resistance-breaking in plant viruses have focused on within-host multiplication without considering other fitness components, which may limit understanding of virus evolution. We have reported that host range expansion of tobamoviruses on L-gene resistant pepper genotypes was associated with severe within-host multiplication penalties. Here, we analyze whether resistance-breaking costs might affect virus survival in the environment by comparing tobamovirus pathotypes differing in infectivity on L-gene resistance alleles. We predicted particle stability from structural models, analyzed particle stability in vitro, and quantified virus accumulation in different plant organs and virus survival in the soil. Survival in the soil differed among tobamovirus pathotypes and depended on differential stability of virus particles. Structure model analyses showed that amino acid changes in the virus coat protein (CP) responsible for resistance-breaking affected the strength of the axial interactions among CP subunits in the rod-shaped particle, thus determining its stability and survival. Pathotypes ranked differently for particle stability/survival and for within-host accumulation. Resistance-breaking costs in survival add to, or subtract from, costs in multiplication according to pathotype. Hence, differential pathotype survival should be considered along with differential multiplication to understand the evolution of the virus populations. Results also show that plant resistance, in addition to selecting for resistance-breaking and for decreased multiplication, also selects for changes in survival, a trait unrelated to the host-pathogen interaction that may condition host range expansion.
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Affiliation(s)
- Aurora Fraile
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA) and E.T.S.I. Agrónomos, Campus de Montegancedo, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain
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Caffier V, Lasserre-Zuber P, Giraud M, Lascostes M, Stievenard R, Lemarquand A, van de Weg E, Expert P, Denancé C, Didelot F, Le Cam B, Durel CE. Erosion of quantitative host resistance in the apple×Venturia inaequalis pathosystem. INFECTION GENETICS AND EVOLUTION 2014; 27:481-9. [PMID: 24530903 DOI: 10.1016/j.meegid.2014.02.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 01/31/2014] [Accepted: 02/07/2014] [Indexed: 12/20/2022]
Abstract
Theoretical approaches predict that host quantitative resistance selects for pathogens with a high level of pathogenicity, leading to erosion of the resistance. This process of erosion has, however, rarely been experimentally demonstrated. To investigate the erosion of apple quantitative resistance to scab disease, we surveyed scab incidence over time in a network of three orchards planted with susceptible and quantitatively resistant apple genotypes. We sampled Venturiainaequalis isolates from two of these orchards at the beginning of the experiment and we tested their quantitative components of pathogenicity (i.e., global disease severity, lesion density, lesion size, latent period) under controlled conditions. The disease severity produced by the isolates on the quantitatively resistant apple genotypes differed between the sites. Our study showed that quantitative resistance may be subject to erosion and even complete breakdown, depending on the site. We observed this evolution over time for apple genotypes that combine two broad-spectrum scab resistance QTLs, F11 and F17, showing a significant synergic effect of this combination in favour of resistance (i.e., favourable epistatic effect). We showed that isolates sampled in the orchard where the resistance was inefficient presented a similar level of pathogenicity on both apple genotypes with quantitative resistance and susceptible genotypes. As a consequence, our results revealed a case where the use of quantitative resistance may result in the emergence of a generalist pathogen population that has extended its pathogenicity range by performing similarly on susceptible and resistant genotypes. This emphasizes the need to develop quantitative resistances conducive to trade-offs within the pathogen populations concerned.
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Affiliation(s)
- Valérie Caffier
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, SFR 4207 QUASAV, 49071 Beaucouzé Cedex, France; AgroCampus-Ouest, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France; Université d'Angers, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France.
| | - Pauline Lasserre-Zuber
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, SFR 4207 QUASAV, 49071 Beaucouzé Cedex, France; AgroCampus-Ouest, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France; Université d'Angers, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France
| | - Michel Giraud
- CTIFL - Centre Technique Interprofessionnel des Fruits et Légumes, Centre de Lanxade, 24130 Prigonrieux, France
| | - Matthieu Lascostes
- CRRG - Centre Régional de Ressources Génétiques, Ferme du Héron, 59650 Villeneuve d'Ascq, France
| | - René Stievenard
- CRRG - Centre Régional de Ressources Génétiques, Ferme du Héron, 59650 Villeneuve d'Ascq, France
| | - Arnaud Lemarquand
- INRA, Unité Expérimentale Horticole N°34 0449, Centre d'Angers-Nantes, 49071 Beaucouzé Cedex, France
| | - Eric van de Weg
- Plant Breeding, Wageningen University and Research Centre, Droevendaalsesteeg 1, P.O. Box 16, 6700 AA Wageningen, The Netherlands
| | - Pascale Expert
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, SFR 4207 QUASAV, 49071 Beaucouzé Cedex, France; AgroCampus-Ouest, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France; Université d'Angers, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France
| | - Caroline Denancé
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, SFR 4207 QUASAV, 49071 Beaucouzé Cedex, France; AgroCampus-Ouest, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France; Université d'Angers, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France
| | - Frédérique Didelot
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, SFR 4207 QUASAV, 49071 Beaucouzé Cedex, France; AgroCampus-Ouest, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France; Université d'Angers, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France
| | - Bruno Le Cam
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, SFR 4207 QUASAV, 49071 Beaucouzé Cedex, France; AgroCampus-Ouest, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France; Université d'Angers, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France
| | - Charles-Eric Durel
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, SFR 4207 QUASAV, 49071 Beaucouzé Cedex, France; AgroCampus-Ouest, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France; Université d'Angers, UMR1345 Institut de Recherche en Horticulture et Semences - IRHS, 49045 Angers, France
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35
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Durable resistance: a key to sustainable management of pathogens and pests. INFECTION GENETICS AND EVOLUTION 2014; 27:446-55. [PMID: 24486735 DOI: 10.1016/j.meegid.2014.01.011] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 12/24/2013] [Accepted: 01/13/2014] [Indexed: 11/22/2022]
Abstract
This review briefly addresses what has been learned about resistance durability in recent years, as well as the questions that still remain. Molecular analyses of major gene interactions have potential to contribute to both breeding for resistance and improved understanding of virulence impacts on pathogen fitness. Though the molecular basis of quantitative resistance is less clear, substantial evidence has accumulated for the relative simplicity of inheritance. There is increasing evidence for specific interactions with quantitative resistance, though implications of this for durability are still unknown. Mechanisms by which resistance gene pyramids contribute to durability remain elusive, though ideas have been generated for identifying gene combinations that may be more durable. Though cultivar mixtures and related approaches have been used successfully, identifying the diseases and conditions that are most conducive to the use of diversity has been surprisingly difficult, and the selective influence of diversity on pathogen populations is complex. The importance of considering resistance durability in a landscape context has received increasing emphasis and is an important future area of research. Experimental systems are being developed to test resistance gene deployment strategies that previously could be addressed only with logic and observation. The value of molecular markers for identifying and pyramiding major genes is quite clear, but the successful use of quantitative trait loci (QTL) for marker-assisted selection of quantitative resistance will depend greatly on the degree to which the identified QTL are expressed in different genetic backgrounds. Transgenic approaches will likely provide opportunities for control of some recalcitrant pathogens, though issues of durability for transgenes are likely to be no different than other genes for resistance. The need for high quality phenotypic analysis and screening methodologies is a priority, and field-based studies are likely to remain of signal importance in the foreseeable future.
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Leroy T, Le Cam B, Lemaire C. When virulence originates from non-agricultural hosts: new insights into plant breeding. INFECTION GENETICS AND EVOLUTION 2014; 27:521-9. [PMID: 24412509 DOI: 10.1016/j.meegid.2013.12.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 12/11/2013] [Accepted: 12/30/2013] [Indexed: 12/27/2022]
Abstract
Monogenic plant resistance breakdown is a model for testing evolution in action in pathogens. As a rule, plant pathologists argue that virulence - the allele that allows pathogens to overcome resistance - is due to a new mutation at the avirulence locus within the native/endemic population that infects susceptible crops. In this article, we develop an alternative and neglected scenario where a given virulence pre-exists in a non-agricultural host and might be accidentally released or introduced on the matching resistant cultivar in the field. The main difference between the two scenarios is the divergence time expected between the avirulent and the virulent populations. As a consequence, population genetic approaches such as genome scans and Approximate Bayesian Computation methods allow explicit testing of the two scenarios by timing the divergence. This review then explores the fundamental implications of this alternative scenario for plant breeding, including the invasion of virulence or the evolution of more aggressive hybrids, and proposes concrete solutions to achieve a sustainable resistance.
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Affiliation(s)
- Thibault Leroy
- Université d'Angers, IRHS, PRES LUNAM, SFR QUASAV, Boulevard Lavoisier, 49045 Angers, France; INRA, IRHS, PRES LUNAM, SFR QUASAV, Rue Georges Morel, 49071 Beaucouzé, France; Agrocampus Ouest, IRHS, PRES LUNAM, SFR QUASAV, Rue Le Nôtre, 49045 Angers, France
| | - Bruno Le Cam
- Université d'Angers, IRHS, PRES LUNAM, SFR QUASAV, Boulevard Lavoisier, 49045 Angers, France; INRA, IRHS, PRES LUNAM, SFR QUASAV, Rue Georges Morel, 49071 Beaucouzé, France; Agrocampus Ouest, IRHS, PRES LUNAM, SFR QUASAV, Rue Le Nôtre, 49045 Angers, France
| | - Christophe Lemaire
- Université d'Angers, IRHS, PRES LUNAM, SFR QUASAV, Boulevard Lavoisier, 49045 Angers, France; INRA, IRHS, PRES LUNAM, SFR QUASAV, Rue Georges Morel, 49071 Beaucouzé, France; Agrocampus Ouest, IRHS, PRES LUNAM, SFR QUASAV, Rue Le Nôtre, 49045 Angers, France.
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Quenouille J, Vassilakos N, Moury B. Potato virus Y: a major crop pathogen that has provided major insights into the evolution of viral pathogenicity. MOLECULAR PLANT PATHOLOGY 2013; 14:439-52. [PMID: 23480826 PMCID: PMC6638879 DOI: 10.1111/mpp.12024] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
TAXONOMY Potato virus Y (PVY) is the type member of the genus Potyvirus in the family Potyviridae. VIRION AND GENOME PROPERTIES: PVY virions have a filamentous, flexuous form, with a length of 730 nm and a diameter of 12 nm. The genomic RNA is single stranded, messenger sense, with a length of 9.7 kb, covalently linked to a viral-encoded protein (VPg) at the 5' end and to a 3' polyadenylated tail. The genome is expressed as a polyprotein of approximately 3062 amino acid residues, processed by three virus-specific proteases into 11 mature proteins. HOSTS PVY is distributed worldwide and has a broad host range, consisting of cultivated solanaceous species and many solanaceous and nonsolanaceous weeds. It is one of the most economically important plant pathogens and causes severe diseases in cultivated hosts, such as potato, tobacco, tomato and pepper, as well as in ornamental plants. TRANSMISSION PVY is transmitted from plant to plant by more than 40 aphid species in a nonpersistent manner and, in potato, by planting contaminated seed tubers. DIVERSITY: Five major clades, named C1, C2, Chile, N and O, have been described within the PVY species. In recent decades, a strong increase in prevalence of N × O recombinant isolates has been observed worldwide. A correlation has been observed between PVY phylogeny and certain pathogenicity traits. GENETIC CONTROL OF PVY: Resistance genes against PVY have been used widely in breeding programmes and deployed in the field. These resistance genes show a large diversity of spectrum of action, durability and genetic determinism. Notably, recessive and dominant major resistance genes show highly contrasting patterns of interaction with PVY populations, displaying rapid co-evolution or stable relationships, respectively.
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Affiliation(s)
- Julie Quenouille
- INRA, UR407 Pathologie Végétale, Domaine Saint Maurice, CS 60094, F-84143 Montfavet Cedex, France
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Zhan J, McDonald BA. Experimental measures of pathogen competition and relative fitness. ANNUAL REVIEW OF PHYTOPATHOLOGY 2013; 51:131-53. [PMID: 23767846 DOI: 10.1146/annurev-phyto-082712-102302] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Competition among pathogen strains for limited host resources can have a profound effect on pathogen evolution. A better understanding of the principles and consequences of competition can be useful in designing more sustainable disease management strategies. The competitive ability and relative fitness of a pathogen strain are determined by its intrinsic biological properties, the resistance and heterogeneity of the corresponding host population, the population density and genetic relatedness of the competing strains, and the physical environment. Competitive ability can be inferred indirectly from fitness components, such as basic reproduction rate or transmission rate. However, pathogen strains that exhibit higher fitness components when they infect a host alone may not exhibit a competitive advantage when they co-infect the same host. The most comprehensive measures of competitive ability and relative fitness come from calculating selection coefficients in a mixed infection in a field setting. Mark-release-recapture experiments can be used to estimate fitness costs associated with unnecessary virulence and fungicide resistance.
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Affiliation(s)
- Jiasui Zhan
- Key Lab for Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
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